[fewtch]

Can't believe I didn't think of this before, but this morning I made a simple battery pack for my Creek OBH-11 (two 9v batteries wired in series). I cadged the right size plug for the DC jack from an old AC adapter I had lying around (got a pile of 'em, probably like most people). I had a rat shack enclosure I used, but a "frankenstein" battery pack held together with a rubber band would work just as well. The only thing most people would have to buy is two 9v battery clips from rat shack, and make sure to wire it up with the tip of the DC plug "center positive." Might take a cheap multimeter or polarity tester to figure this part out, but it could probably be fudged.

The result is 18VDC going to the amp rather than the usual 24VDC, but it doesn't seem to make any difference to the gain of the amp.

The difference is not subtle -- the amp sounds dramatically better than when it was running on an Elpac WM080 linear regulated wall wart. The difference between the OBH-1 (nonregulated) and batteries should be not only dramatic, but stunning and unbelievable -- like an entirely different amp. I am completely sold on battery power for headphone amps after this.

Just thought I'd pass this info along... suddenly the Creek (which I was thinking of selling) is in the running again as my main amp, as it synergizes very well with Senn HD600s (in any case, I'm not selling it now). We'll have to see what battery life looks like with different types of 9v batteries.

 

[Hirsch]

I believe that Ray-O-Vac made an NiMH rechargeable that was rated at 7.2 volts. Three of those in series would get you 21.6 volts, closer to the Creek's rated power. OTOH, three NiMH rated at 8.4 v gets you to 25.2 volts, a little hot but probably not enough to hurt anything.

This actually gave me an interesting idea to try with the Sennheiser HEV 70 amp. It would only require 16 alkaline "D" cells wired in series... (or 20 NiMH "D" cells...

)

 

[Musicfan123]

Now you guys got me started, I'm putting together a battery pack for my new Rotel integrated.

 

[fewtch]

Quote:

Originally posted by Hirsch I believe that Ray-O-Vac made an NiMH rechargeable that was rated at 7.2 volts. Three of those in series would get you 21.6 volts, closer to the Creek's rated power.

Probably a good idea. I found that the amp was clipping at higher volumes (on orchestral peaks and such) with the battery pack as it is using two NiMH batteries -- I think the voltage was just too low.

Using two 9v alkaline batteries solved the problem temporarily, but I like your idea of using three lower-rated NiMH batteries instead. Particularly if the alkalines don't hold up long and the clipping starts again, I'll be taking your advice and buying a few more NiMH rechargeables early next month. Or I'll just use the regulated wall wart with the Creek (I'm probably relegating it to bedside status), but will definitely be using batteries with the Meta42 I have coming in next week.

 

[Sovkiller]

Well in principle this is the main purpose of a good power supply, to give the amp be as good DC, as a battery....so is not weird that the things go better....BTW if you want the things go even better, I have heard that a simple replacement of the caps inside the amp, for a better quality ones, make it sound day and night form the stock OBH-11....

 

[jpelg]

Quote:

Now you guys got me started, I'm putting together a battery pack for my new Rotel integrated.

LOL

!

BTW, nice idea, fewtch! Good to see some ingenuity bearing some new fruit.

 

[fewtch]

Quote:

Originally posted by Sovkiller Well in principle this is the main purpose of a good power supply, to give the amp be as good DC, as a battery....so is not weird that the things go better....BTW if you want the things go even better, I have heard that a simple replacement of the caps inside the amp, for a better quality ones, make it sound day and night form the stock OBH-11....

I know... but I don't have any circuit diagrams or layouts of the Creek and don't trust myself to do the mods (still a beginner with a soldering iron and with circuits). It's not worth it either for a $100 amp to send it to someone and pay them to do it for me... even with better caps it's still not as good as a maxed out Meta42, I think (which is just a better design and all parts are better, not just the caps).

I don't really want to put any more $$ into an amp this cheap, it will have to be serviceable at whatever SQ it puts out with clean power. If you like modding things then do it with your stuff... to me it's not worth it, and not worth risking the damage either. I think my next step is not modding, but building... maybe a CMOY first, then maybe later a PPA.

 

[Sovkiller]

fewtch listen, usually I do not mod things neither, but just as you are not willing to spen too much money on any other amp, I do believe that a mod will be cheaper, and in the case of caps very simle also, is just plug and play, knowing the values and polarity, (in that case) but anyway if you want a better amp, and decide to go DIY, and do not want to pay someone to do it, with more experience and knowledge, I think that if you are careful enough, and read the diagrams, all the tangent pages, and even the same boards, you will have no problems in filling a PPA board, in a decent way, but the the hard part is, if something goes wrong, to troubleshoot it later, I do not feel comfortable myself, neither, to do it, that is why I simply relied on another person for that.....always a DIY will be cheaper and better bang for the buck, than a good comercial amp....

 

[Canman]

Quote:

Originally posted by Musicfan123 Now you guys got me started, I'm putting together a battery pack for my new Rotel integrated.

You would need a ton of batteries to run a speaker amp. I once had an N.E.W. DCA-66 amp that ran 66 watts of Class A power from 4 motorcycle batteries. The battery case was 100 pounds, not exaggerating. The had virtually no noise, it was pretty amazing.

 

[DesBen]

Two 12V car batteries in series would give you that spec 24V. And you'd only have to charge it once in a blue moon.

 

[Musicfan123]

Cool, then I'll plan a weekend trip to the local junkyard.

 

[Dusty Chalk]

Do a search for "Creek" with user set to "kwkarth" -- he's already done this.

 

[fewtch]

Quote:

Originally posted by Dusty Chalk Do a search for "Creek" with user set to "kwkarth" -- he's already done this.

Great minds think alike, I guess...